Python Commands from Terminal Aren't Working Ubuntu 13.10
As mentioned by sambler, the terminal from which blender is started is not normally used as an interactive python console. (however it is possible)

Usually one uses the python console built into the GUI.

The python console is an editor just like the 3D view or the text editor, so you can arrange your screen layout however you like to incorporate it with your workflow. 

For example:



You can even split an editor into a separate window (as in the kind handled by the window manager).
This can be accomplished by pressing ShiftLMB on the area splitting corner and dragging, or by selecting the option from the editor areas menu:



For example:



Note that you probably still want the terminal from which blender was started open, as any error messages/warnings are printed to stdout and will appear there  (they will not appear in the interface by default, but there is a workaround).